com.joyveb.dbpimpl.cass.prepare.convert.RowReaderPropertyAccessor.java Source code

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Here is the source code for com.joyveb.dbpimpl.cass.prepare.convert.RowReaderPropertyAccessor.java

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/*
 * Copyright 2013 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.joyveb.dbpimpl.cass.prepare.convert;

import java.nio.ByteBuffer;

import org.springframework.expression.EvaluationContext;
import org.springframework.expression.PropertyAccessor;
import org.springframework.expression.TypedValue;

import com.datastax.driver.core.DataType;
import com.datastax.driver.core.Row;

/**
 * {@link PropertyAccessor} to read values from a {@link Row}.
 * 
 * @author Alex Shvid
 */
enum RowReaderPropertyAccessor implements PropertyAccessor {

    INSTANCE;

    /* 
     * (non-Javadoc)
     * @see org.springframework.expression.PropertyAccessor#getSpecificTargetClasses()
     */
    public Class<?>[] getSpecificTargetClasses() {
        return new Class<?>[] { Row.class };
    }

    /* 
     * (non-Javadoc)
     * @see org.springframework.expression.PropertyAccessor#canRead(org.springframework.expression.EvaluationContext, java.lang.Object, java.lang.String)
     */
    public boolean canRead(EvaluationContext context, Object target, String name) {
        return ((Row) target).getColumnDefinitions().contains(name);
    }

    /* 
     * (non-Javadoc)
     * @see org.springframework.expression.PropertyAccessor#read(org.springframework.expression.EvaluationContext, java.lang.Object, java.lang.String)
     */
    public TypedValue read(EvaluationContext context, Object target, String name) {
        Row row = (Row) target;
        if (row.isNull(name)) {
            return TypedValue.NULL;
        }
        DataType columnType = row.getColumnDefinitions().getType(name);
        ByteBuffer bytes = row.getBytes(name);
        Object object = columnType.deserialize(bytes);
        return new TypedValue(object);
    }

    /* 
     * (non-Javadoc)
     * @see org.springframework.expression.PropertyAccessor#canWrite(org.springframework.expression.EvaluationContext, java.lang.Object, java.lang.String)
     */
    public boolean canWrite(EvaluationContext context, Object target, String name) {
        return false;
    }

    /* 
     * (non-Javadoc)
     * @see org.springframework.expression.PropertyAccessor#write(org.springframework.expression.EvaluationContext, java.lang.Object, java.lang.String, java.lang.Object)
     */
    public void write(EvaluationContext context, Object target, String name, Object newValue) {
        throw new UnsupportedOperationException();
    }

}